When I started at Harvard Law School, they told all incoming students a story that I've found applies in a lot of situations (not including law school, for which the story was wildly inappropriate). Two people are sleeping in a tent in the woods. They awaken to the sound of a bear crashing through the forest toward their tent. One person starts to put on his shoes. The other says "why would you possibly put on your shoes -- there is no way you can outrun a bear." The response is "I don't need to outrun the bear. I just need to outrun you."
My dad just needs to outrun the Merkel Cell carcinoma. He doesn't need to defeat the bear, just to keep the bear in his rearview mirror. Of course, I prefer a complete defeat of the bear.
I hope, if I ever face a similar health crisis, that I can keep a good sense of perspective, and treat each new day as a gift to be opened, explored, and cherished. Thanks, dad, for providing a poignant example of how to outrun the bear and enjoy the scenery during the run. Your family is right there by your side every step of the way.